Green Toxicology LLC
106 Sumner Road
Brookline, MA 02445
T: 617.835.0093


Toxicology of Environmental Chemicals

We encounter exogenous chemicals at every turn - in water, air, soil, consumer products, food, and drugs, at home, outdoors, and in the workplace. Toxicologic data on the effects of chemicals are frequently generated through controlled studies of laboratory animals, such as rats and guinea pigs, but are also gathered through observation of humans exposed deliberately (for example, to sulfur dioxide), unintentionally (for example, to water pollutants or food contaminants), or knowingly (for example, to a solvent in the workplace). Epidemiologic studies of exposed populations also give useful information.

Questions regarding the safety of exposure to environmental chemicals may arise before or after the fact. A drug manufacturer, for instance, may want to know at what concentration in air a reactant might cause injury during a brief, acute exposure, such as might occur during breakdown of manufacturing equipment, to aid in planning for emergencies. As another example, people who discover that their drinking water has been contaminated for many years by perchlorate may want to know whether their past or current health problems were caused by that exposure.

Sample Projects

Toxicity of a mineral-processing agent

For the State of Vermont, we led the state's most intensive and extensive evaluation of the environmental and health impacts of industrial waste management. We discovered the first instance of groundwater contamination by a teratogenic (i.e., birth defect-inducing) chemical, aminoethylethanolamine, researched the toxicity of this agent, and developed a water quality guideline for this chemical that was then adopted by the state.

Birth defects and industrial chemicals

For a group of manufacturers in the high-technology industry, we conducted extensive reviews of the reproductive and developmental toxicity of numerous chemicals to which workers may have been exposed. Developmental toxicity, or the ability of a chemical to adversely affect fetal development, was of concern because of the occurrence of birth defects in some children of workers. We exhaustively searched the open and "gray" literature for toxicologic, epidemiologic, and other data describing the effects of the industrial chemicals on humans or laboratory animals, and assembled this information in a form useful to the clients.

Asthma and short-term exposure to sulfur dioxide (SO2)

We evaluated the technical bases of U.S. EPA's 2009 revision of the Primary National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (SO2). We identified and, to the extent possible, corrected key analytical problems, and demonstrated the consequences of the corrected values with respect to health policy-making.

Asphalt fumes and related mixtures and chemicals

Since 1997, we have served as advisors to the makers and users of hot-mix asphalt. We have been involved in the design and interpretation of applied research regarding asphalt fume exposure assessment and toxicology. We have submitted detailed comments to (i) the National Institute of Occupational Safety and Health (NIOSH) on health effects issues surrounding asphalt fumes, and (ii) the U.S. EPA regarding the magnitude and nature of hazardous air pollutant emissions that may occur when hot-mix asphalt is loaded onto trucks. We have performed detailed estimates of hot-mix asphalt plant emissions, used computer-based models to predict the dispersion and dilution of these pollutants in the environment, compared both the emissions and predicted concentrations with ambient measurements, and assessed the potential for exposures to the pollutants to lead to adverse health effects.